Wireless audio system and method for wirelessly communicating audio information using the same

ABSTRACT

Embodiments of wireless audio systems and methods for wirelessly communicating audio information are disclosed herein. In one example, a wireless audio system includes a first and a second wireless headphones. The first wireless headphone is configured to receive, from an audio source, audio information using a short-range wireless communication; in response to successfully receiving the audio information, generate an error correcting code based on the audio information; and transmit an error correcting message including the error correcting code. The second wireless headphone is configured to receive, from the audio source, the audio information using the short-range wireless communication; receive, from the first wireless headphone, the error correcting message including the error correcting code; and in response to successfully receiving the audio information based on the error correcting code, transmit an ACK message to the audio source. One of the first and second wireless headphones works in a snoop mode to communicate with the audio source based on communication parameters of another one of the first and second wireless headphones.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Chinese PatentApplication No. 201811444750.2 filed on Nov. 29, 2018, and ChinesePatent Application No. 201811479680.4 filed on Dec. 5, 2018, both ofwhich are incorporated herein by reference in their entireties.

BACKGROUND

Embodiments of the present disclosure relate to wireless audio systems.

Loudspeakers, including headphones, have been widely used in daily life.Headphones are a pair of small loudspeaker drivers worn on or around thehead over a user's ears, which convert an electrical signal to acorresponding sound.

Wired headphones, however, constrain the users' movement because of thewires (cords), and are particularly inconvenient during exercise.Conventional wireless headphones no longer need the wires between theheadphones and the audio sources, but still require the wires betweenthe left and right headphones.

SUMMARY

Embodiments of wireless audio systems and methods for wirelesslycommunicating audio information are disclosed herein.

In one example, a wireless audio system includes a first wirelessheadphone and a second wireless headphone. The first wireless headphoneis configured to receive, from an audio source, audio information usinga first type of short-range wireless communication; in response tosuccessfully receiving the audio information from the audio source,generate an error correcting code based on the audio information; andtransmit an error correcting message including the error correctingcode. The second wireless headphone is configured to receive, from theaudio source, the audio information using the first type of short-rangewireless communication; receive, from the first wireless headphone, theerror correcting message including the error correcting code; and inresponse to successfully receiving the audio information from the audiosource based on the error correcting code, transmit an acknowledgement(ACK) message to the audio source. One of the first and second wirelessheadphones works in a snoop mode to communicate with the audio sourcebased on communication parameters of another one of the first and secondwireless headphones.

In another example, a method for wirelessly communicating audioinformation is disclosed. Audio information is received by a firstwireless headphone from an audio source using a first type ofshort-range wireless communication. In response to successfullyreceiving the audio information from the audio source, an errorcorrecting code is generated by the first wireless headphone based onthe audio information. An error correcting message including the errorcorrecting code is transmitted by the first wireless headphone. Theaudio information is received by a second wireless headphone from theaudio source using the first type of short-range wireless communication.The error correcting message including the error correcting code isreceived by the second wireless headphone from the first wirelessheadphone. In response to successfully receiving the audio informationfrom the audio source based on the error correcting code, an ACK messageis transmitted by the second wireless headphone to the audio source.

In still another example, a method for wirelessly communicatingBLUETOOTH audio information is disclosed. A BLUETOOTH audio data packetis received from an audio source using BLUETOOTH communication. Inresponse to successfully receiving the BLUETOOTH audio data packet fromthe audio source, an error correcting code is generated by coding apayload of the BLUETOOTH audio data packet. An error correcting messageincluding the error correcting code is transmitted to a wirelessheadphone.

In yet another example, a method for wirelessly communicating BLUETOOTHaudio information is disclosed. A BLUETOOTH audio data packet isreceived from an audio source using BLUETOOTH communication. An errorcorrecting message including an error correcting code is received from awireless headphone. The BLUETOOTH audio data packet from the audiosource is corrected based on the error correcting code. In response tosuccessfully receiving the BLUETOOTH audio data packet after thecorrection, an ACK message is transmitted to the audio source.

This Summary is provided merely for purposes of illustrating someembodiments to provide an understanding of the subject matter describedherein. Accordingly, the above-described features are merely examplesand should not be construed to narrow the scope or spirit of the subjectmatter in this disclosure. Other features, aspects, and advantages ofthis disclosure will become apparent from the following DetailedDescription, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate the presented disclosure and, togetherwith the description, further serve to explain the principles of thedisclosure and enable a person of skill in the relevant art(s) to makeand use the disclosure.

FIGS. 1A-1D are block diagrams illustrating an exemplary wireless audiosystem in accordance with various embodiments.

FIG. 2 is a detailed block diagram of the exemplary wireless audiosystem in FIGS. 1A-1D in accordance with an embodiment.

FIG. 3 is a block diagram illustrating an exemplary wireless headphonein accordance with an embodiment.

FIGS. 4A-4E are timing diagrams of exemplary wireless audio systems inaccordance with various embodiments.

FIGS. 5A and 5B are depictions of exemplary BLUETOOTH audio data packetsin accordance with an embodiment.

FIG. 6 is a depiction of a header of an exemplary packet in accordancewith an embodiment.

FIG. 7 is a flow chart illustrating an exemplary method for wirelesslycommunicating audio information in accordance with an embodiment.

FIG. 8 is a flow chart illustrating another exemplary method forwirelessly communicating audio information in accordance with anembodiment.

FIG. 9 is a flow chart illustrating still another exemplary method forwirelessly communicating audio information in accordance with anembodiment.

FIG. 10 is a flow chart illustrating yet another exemplary method forwirelessly communicating audio information in accordance with anembodiment.

FIG. 11 is a flow chart illustrating yet another exemplary method forwirelessly communicating audio information in accordance with anembodiment.

The presented disclosure is described with reference to the accompanyingdrawings. In the drawings, generally, like reference numbers indicateidentical or functionally similar elements. Additionally, generally, theleft-most digit(s) of a reference number identifies the drawing in whichthe reference number first appears.

DETAILED DESCRIPTION

Although specific configurations and arrangements are discussed, itshould be understood that this is done for illustrative purposes only.It is contemplated that other configurations and arrangements can beused without departing from the spirit and scope of the presentdisclosure. It is further contemplated that the present disclosure canalso be employed in a variety of other applications.

It is noted that references in the specification to “one embodiment,”“an embodiment,” “an example embodiment,” “some embodiments,” etc.,indicate that the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases do not necessarily refer to the same embodiment. Further,when a particular feature, structure or characteristic is described inconnection with an embodiment, it is contemplated that such feature,structure or characteristic may also be used in connection with otherembodiments whether or not explicitly described.

In general, terminology may be understood at least in part from usage incontext. For example, the term “one or more” as used herein, dependingat least in part upon context, may be used to describe any feature,structure, or characteristic in a singular sense or may be used todescribe combinations of features, structures or characteristics in aplural sense. Similarly, terms, such as “a,” “an,” or “the,” again, maybe understood to convey a singular usage or to convey a plural usage,depending at least in part upon context. In addition, the term “basedon” may be understood as not necessarily intended to convey an exclusiveset of factors and may, instead, allow for existence of additionalfactors not necessarily expressly described, again, depending at leastin part on context.

True wireless stereo (TWS) headphones (also known as untetheredheadphones) is a type of wireless headphones that remove the wiresbetween the left and right headphones. In some TWS headphones, a primarywireless headphone can simultaneously communicate with an audio sourceand a secondary wireless headphone. For example, the audio sourcetransmits data (music, audio, or data packets) to the primary wirelessheadphone using BLUETOOTH, and the primary wireless headphone thenforwards the data to the secondary wireless headphone. This approach cancause the high power consumption of the primary wireless headphone.Also, the physical structures of the human head between the left andright ears can affect the data transmission quality between the primaryand secondary wireless headphones, such as causing lagging and/or highlatency.

As will be disclosed in detail below, among other novel features, thewireless audio systems disclosed herein can achieve “true wirelessstereo” with improved data transmission quality and reduced headphonepower consumption. In some embodiments of the present disclosure, theprimary wireless headphone establishes a normal communication link withthe audio source to receive the audio data (e.g., stereo audio), whilethe secondary wireless headphone establishes a snoop communication linkwith the audio source to snoop communications on the normalcommunication link and receive the audio data from the audio source aswell. Having the secondary wireless headphone work in the snoop mode canreduce the power consumption of the primary wireless headphone becausethe primary wireless headphone no longer needs to forward the audio datato the secondary wireless headphone.

Moreover, one of the primary and secondary wireless headphones, whichsuccessfully receives the audio data from the audio source, can transmitan error correcting message including an error correcting code (ECC)based on the successfully-received audio data to the other wirelessheadphone. The ECC can be used to correct the error in the audio datareceived by the other wireless headphone without re-transmitting theaudio data, thereby reducing the times of re-transmission and improvingthe system reliability.

Additional novel features will be set forth in part in the descriptionwhich follows, and in part will become apparent to those skilled in theart upon examination of the following and the accompanying drawings ormay be learned by production or operation of the examples. The novelfeatures of the present disclosure may be realized and attained bypractice or use of various aspects of the methodologies,instrumentalities, and combinations set forth in the detailed examplesdiscussed below.

FIG. 1A is a block diagram illustrating an exemplary wireless audiosystem 100 in accordance with an embodiment. Wireless audio system 100may include an audio source 102, a primary wireless headphone 104, and asecondary wireless headphone 106. Audio source 102 may be any suitabledevice that can provide audio information including, for example, musicor voice in the digital or analog format. Audio source 102 may include,but is not limited to, a handheld device (e.g., dumb or smart phone,tablet, etc.), a wearable device (e.g., eyeglasses, wrist watch, etc.),a radio, a music player, an electronic musical instrument, an automobilecontrol station, a gaming console, a television set, a laptop computer,a desktop computer, a netbook computer, a media center, a set-top box, aglobal positioning system (GPS), or any other suitable device. Primarywireless headphone 104 and secondary wireless headphone 106 may be apair of loudspeakers that can be worn on or around the head over auser's ears. Primary wireless headphone 104 and secondary wirelessheadphone 106 may be any electroacoustic transducers that convert anelectrical signal (e.g., representing the audio information provided byaudio source 102) to a corresponding sound. In some embodiments, eachprimary wireless headphone 104 and secondary wireless headphone 106 maybe an earbud (also known as earpiece) that can plug into the user's earcanal. In some embodiments, primary wireless headphone 104 and secondarywireless headphone 106 may be TWS headphones, which are individual unitsthat are not physically held by a band over the head and/or electricallyconnected by a cord. Primary wireless headphone 104 and/or secondarywireless headphone 106 may be combined with a microphone to form aheadset according to some embodiments. It is understood that although inFIG. 1A, wireless audio system 100 includes both audio source 102 andthe pair of primary and secondary wireless headphones 104 and 106, insome embodiments, wireless audio system 100 may include only primarywireless headphone 104 and secondary wireless headphone 106.

As shown in FIG. 1A, bidirectional communications may be establishedbetween audio source 102 and primary wireless headphone 104 and betweenaudio source 102 and secondary wireless headphone 106. In someembodiments, a normal communication link may be established betweenaudio source 102 and primary wireless headphone 104 using a short-rangewireless communication (e.g., the BLUETOOTH communication or WiFicommunication). That is, primary wireless headphone 104 may work in thenormal mode. In the normal mode, primary wireless headphone 104 mayreceive audio information (e.g., in data packets) transmitted by acarrier wave from audio source 102 via the normal communication link. Insome embodiments, audio information may be a stream of audio stereoinformation in the form of compressed or uncompressed stereo samples forfirst and second audio channels, such as left-channel audio informationand right-channel audio information or the like. The normalcommunication link may be bidirectional such that primary wirelessheadphone 104 may transmit messages back to audio source 102 in responseto the reception of the audio information from audio source 102. Asdescribed below in detail, in some embodiments, primary wirelessheadphone 104 transmit negative acknowledgement (NACK) messages to audiosource 102 in response to not successfully receiving the audioinformation from audio source 102. In some embodiments, the short-rangewireless communication between audio source 102 and primary wirelessheadphone 104 is a unidirectional communication link in which primarywireless headphone 104 receives the audio information from audio source102, but does not transmit data (e.g., NACK messages) back to audiosource 102.

In some embodiments, a snoop communication link may be establishedbetween audio source 102 and secondary wireless headphone 106 using thesame short-range wireless communication between audio source 102 andprimary wireless headphone 104 (e.g., the BLUETOOTH or WiFi). That is,secondary wireless headphone 106 may work in the snoop mode in which theconnection with secondary wireless headphone 106 may not be known byaudio source 102. In the snoop mode, secondary wireless headphone 106may snoop (also known as “listen” or “eavesdrop”) the communicationsbetween audio source 102 and primary wireless headphone 104 on thenormal communication link. By snooping the communications between audiosource 102 and primary wireless headphone 104, secondary wirelessheadphone 106 may also receive the audio information (e.g., in datapackets) transmitted by the carrier wave from audio source 102 via thesnoop communication link. The snoop communication link may bebidirectional such that secondary wireless headphone 106 may transmitmessages back to audio source 102 in response to the reception of theaudio information from audio source 102. As described below in detail,the messages transmitted by secondary wireless headphone 106 mayinclude, for example, acknowledgement (ACK) messages and NACK messages.

In some embodiments, audio information may be transmitted by audiosource 102 according to the BLUETOOTH protocol at the working radiofrequency (RF) band between 2,402 MHz and 2,480 MHz or between 2,400 MHzand 2,483.5 MHz (referred to herein as “2.4 GHz”). BLUETOOTH is awireless technology standard for exchanging data over short distances,and the BLUETOOTH protocol is one example of short-range wirelesscommunication protocols. In one example, audio source 102 may apply theadvanced audio distribution profile (A2DP) of the BLUETOOTH protocol fortransmitting the audio information. For example, based on the A2DP, aBLUETOOTH audio streaming of music or voice may be streamed from audiosource 102 to primary and secondary wireless headphones 104 and 106 overBLUETOOTH connections. In some embodiments, audio information may betransmitted by audio source 102 according to the WiFi protocol at theworking RF band of 2.4 GHz or 5 GHz. WiFi is a wireless technology forwireless local area networking based on the IEEE 802.11 standards, andthe WiFi protocol (also known as the 802.11 protocol) is another exampleof short-range wireless communication protocols. It is understood thatthe transmission of the audio information by audio source 102 may beusing any other suitable short-range wireless communication besidesBLUETOOTH and WiFi.

As shown in FIG. 1A, to enable secondary wireless headphone 106 work inthe snoop mode, primary wireless headphone 104 may transmit, tosecondary wireless headphone 106, communication parameters associatedwith the normal communication link between audio source 102 and primarywireless headphone 104. The communication parameters may include, butare not limited to, the address of audio source 102 (e.g., the IPaddress or media access control (MAC) address) and the encryptionparameters between audio source 102 and primary wireless headphone 104.The transmission of the communication parameters may be carried on by ashort-range wireless communication that is the same type as that fortransmitting the audio information by audio source 102 or a differenttype short-range wireless communication. For example, the short-rangewireless communication may be BLUETOOTH communication or WiFicommunication. In some embodiments, the transmission of thecommunication parameters may be at a frequency lower than the frequencyused for transmitting the audio information by audio source 102 (e.g.,2.4 GHz). For example, near-field magnetic induction (NFMI)communication may be used for transmitting of the communicationparameters. NFMI communication is a short-range wireless communicationby coupling a tight, low-power, non-propagating magnetic field betweendevices. NFMI communication can contain transmission energy within thelocalized magnetic field, which does not radiate into free space. Insome embodiments, the carrier wave frequency for NFMI communication isbetween about 5 MHz and about 50 MHz (e.g., between 5 MHz and 50 MHz),such as between 5 MHz and 40 MHz, between 5 MHz and 30 MHz, between 5MHz and 20 MHz, between 5 MHz and 10 MHz, between 15 MHz and 50 MHz,between 25 MHz and 50 MHz, between 35 MHz and 50 MHz, and between 45 MHzand 50 MHz. In some embodiments, the carrier wave frequency is about 10MHz (e.g., 10 MHz) or about 13.56 MHz (e.g., 13.56 MHz).

Upon receiving the communication parameters from primary wirelessheadphone 104, secondary wireless headphone 106 can establish the snoopcommunication link with audio source 102 based on the communicationparameters. For example, secondary wireless headphone 106 may pretend tobe primary wireless headphone 104 so that audio source 102 does notrecognize secondary wireless headphone 106 as a newly-connected deviceand thus, will not disconnect and reconnect with secondary wirelessheadphone 106.

In response to successfully receiving the audio information (e.g., aBLUETOOTH audio data packet) from audio source 102, primary wirelessheadphone 104 may be configured to generate an error correcting code(ECC) based on the audio information (e.g., by coding the payload of theBLUETOOTH audio data packet). Primary wireless headphone 104 then maytransmit an error correcting message (ECC MSG) including the ECC tosecondary wireless headphone 106. The ECC may include, but not limitedto, Reed-Solomon (RS) code, Bose-Chaudhuri-Hocquenghem (BCH) code, etc.In case secondary wireless headphone 106 does not successfully receivethe audio information from audio source 102 (e.g., error found in thepayload of a BLUETOOTH audio data packet), the ECC contained in theerror correcting message from primary wireless headphone 104 may be usedby secondary wireless headphone 106 to correct the audio information(e.g., the error found in the payload of the BLUETOOTH audio datapacket). Also, the transmission of an error correcting message with anECC can also serve as an ACK message indicative of the successfulreception of the audio information by primary wireless headphone 104.Thus, when secondary wireless headphone 106 successfully receives theaudio information from audio source 102 based on the ECC from primarywireless headphone 104, secondary wireless headphone 106 may transmit anACK message to audio source 102 indicative of the successful receptionsof the audio information by both primary and secondary wirelessheadphones 104 and 106. It is understood that secondary wirelessheadphone 106 may successfully receive the audio information from audiosource 102 based on the ECC, either when secondary wireless headphone106 successfully receives the audio information from audio source 102without error at the first place (i.e., without the need of correctionusing the ECC) or when secondary wireless headphone 106 successfullycorrects the audio information from audio source 102 based on the ECC.In either case, secondary wireless headphone 106 is considered as“successfully receiving the audio information from audio source 102based on the ECC.”

The transmission of the error correcting message may be carried on by ashort-range wireless communication that is the same type as that fortransmitting the audio information by audio source 102 or a differenttype short-range wireless communication. For example, the short-rangewireless communication for transmitting the error correcting message maybe BLUETOOTH communication or WiFi communication. The WiFi communicationmay be based on any suitable standards, such as IEEE 802.11b, 802.11d,802.11g, etc. In some embodiments, the transmission of the communicationparameters may be at a frequency lower than the frequency used fortransmitting the audio information by audio source 102 (e.g., 2.4 GHz).For example, NFMI communication may be used for transmitting of theerror correcting message. In some embodiments, the carrier wavefrequency for NFMI communication is between about 5 MHz and about 50 MHz(e.g., between 5 MHz and 50 MHz), such as between 5 MHz and 40 MHz,between 5 MHz and 30 MHz, between 5 MHz and 20 MHz, between 5 MHz and 10MHz, between 15 MHz and 50 MHz, between 25 MHz and 50 MHz, between 35MHz and 50 MHz, and between 45 MHz and 50 MHz. In some embodiments, thecarrier wave frequency is about 10 MHz (e.g., 10 MHz) or about 13.56 MHz(e.g., 13.56 MHz). In some embodiments in which WiFi communication orNFMI communication is used between primary wireless headphone 104 andsecondary wireless headphone 106, instead of transmitting the errorcorrecting messages, primary wireless headphone 104 transmits the entireaudio information (e.g., the entire BLUETOOTH audio data packets) tosecondary wireless headphone 106.

In some embodiments, the reception of the audio information from audiosource 102 is not successful at primary wireless headphone 104, primarywireless headphone 104 may transmit a NACK message to audio source 102.In some embodiments, in response to not successfully receiving the audioinformation from audio source 102, primary wireless headphone 104 maynot transmit the NACK message to audio source 102, but instead,transmitting a pseudo error correcting message without the ECC tosecondary wireless headphone 106 or not transmitting any message tosecondary wireless headphone 106. As to secondary wireless headphone106, in response to at least one of (i) not successfully receiving theaudio information from audio source 102 based on the ECC (indicative ofthe unsuccessful reception of the audio source by secondary wirelessheadphone 106 even with the ECC), or (ii) not successfully receiving theerror correcting message including the ECC from primary wirelessheadphone 104 (indicative of the unsuccessful reception of the audiosource by primary wireless headphone 104), secondary wireless headphone106 may transmit a NACK message to audio source 102. It is understoodthat secondary wireless headphone 106 may not successfully receive theaudio information from audio source 102 even after the correction basedon the ECC, i.e., the ECC correction at secondary wireless headphone 106fails.

FIG. 1B is a block diagram illustrating exemplary wireless audio system100 in accordance with another embodiment. The same functions of audiosource 102, primary wireless headphone 104, and secondary wirelessheadphone 106 that have been described above with respect to FIG. 1Awill not be repeated with respect to FIG. 1B. Different from the exampleof FIG. 1A, in this example, instead of generating the ECC andtransmitting the error correcting message including the ECC by primarywireless headphone 104, secondary wireless headphone 106 may generate anECC based on the audio information in response to successfully receivingthe audio information from audio source 102 and then transmit an errorcorrecting message including the ECC to primary wireless headphone 104.Primary wireless headphone 104 then may receive the error correctingmessage including the ECC from secondary wireless headphone 106 and inresponse to successfully receiving the audio information from audiosource 102 based on the ECC, transmit an ACK message to audio source102.

That is, in implementing the features related to ECC disclosed herein,the roles of primary and secondary wireless headphones can be switched.In other words, either primary or secondary wireless headphone 104 or106 can be the party generating and transmitting the ECC (ECCtransmitting headphone), and either primary or secondary wirelessheadphone 104 or 106 can be the party utilizing the ECC for correctingthe audio information and transmitting the ACK message to audio source102 (ECC receiving headphone). In some embodiments, the ECC transmittingheadphone and the ECC receiving headphone can be dynamically switchedbased on the signal quality of each of the ECC transmitting headphoneand ECC receiving headphone. In some embodiments, the headphone withbetter signal quality is used as ECC transmitting headphone. That is,the signal quality of the ECC transmitting headphone may be better thanthe signal quality of the ECC receiving headphone. As a result, thelikelihood that the ECC transmitting headphone can successfully receivethe audio information from audio source 102 may be increased, therebytransmitting more error correcting messages including the ECC. With moreerror correcting messages including the ECC, the ECC receiving headphonemay correct more audio information with errors, thereby reducing thenumbers of re-transmission and improving the system reliability. In someembodiments, the headphone with better signal quality is used as ECCreceiving headphone. That is, the signal quality of the ECC receivingheadphone may be better than the signal quality of the ECC transmittingheadphone. As a result, the likelihood that audio source 102 cansuccessfully receive the ACK and/or NACK messages from the ECC receivingheadphone may be increased.

FIG. 1C is a block diagram illustrating exemplary wireless audio system100 in accordance with another embodiment. The same functions of audiosource 102, primary wireless headphone 104, and secondary wirelessheadphone 106 that have been described above with respect to FIG. 1Awill not be repeated with respect to FIG. 1C. Different from the exampleof FIG. 1A, in this example, when primary wireless headphone 104successfully receives part of the audio information (e.g., the header ofa BLUETOOTH audio data packet) but fails to receive other parts of theaudio information (e.g., the payload of the BLUETOOTH audio datapacket), primary wireless headphone 104 may transmit a first errorcorrecting message (ECC MSG 1) without an ECC to secondary wirelessheadphone 106. In this situation, when secondary wireless headphone 106successfully receives the audio information from audio source 102 aswell as the first error correcting message without the ECC from primarywireless headphone 104, secondary wireless headphone 106 may generate anECC based on the audio information and transmit a second errorcorrecting message (ECC MSG 2) including the ECC to primary wirelessheadphone 104. Primary wireless headphone 104 then may correct the partof the audio information that fails to be received without the need ofre-transmission.

FIG. 1D is a block diagram illustrating exemplary wireless audio system100 in accordance with another embodiment. The same functions of audiosource 102, primary wireless headphone 104, and secondary wirelessheadphone 106 that have been described above with respect to FIG. 1Cwill not be repeated with respect to FIG. 1D. Similar to therelationship between FIGS. 1A and 1B, as shown in FIGS. 1C and 1D, theECC transmitting headphone that transmits the first error correctingmessage and the ECC receiving headphone that receives the first errorcorrecting message can be switched between primary and secondarywireless headphones 104 and 106.

FIG. 2 is a detailed block diagram of exemplary wireless audio system100 in FIGS. 1A-1D in accordance with an embodiment. Audio source 102 inthis example includes an antenna 202, a radio-frequency (RF) module 204and a physical layer module 206. It is understood that additionalmodule(s) may be included in audio source 102, either in the sameintegrated circuit (IC) chip in which RF module 204 and physical layermodule 206 are formed or in a separate IC chip.

Antenna 202 may include an array of conductors for transmitting andreceiving radio waves at one or more RF bands corresponding to RF module204. For example, antenna 202 may transmit audio information modulatedby a carrier wave using RF module 204. As described above, the audioinformation may be any music and/or voice information provided by audiosource 102. For example, the audio information may be a stream of audiostereo information in the form of compressed or uncompressed stereosamples for first and second audio channels, such as left-channel audioinformation and right-channel audio information or the like. In someembodiments, the audio information may be mono audio information in asingle audio channel or audio information in more than two separateaudio channels (e.g., left, central, and right channels). Antenna 202may also receive the messages modulated by a carrier wave. For example,the messages may be any messages used for acknowledging the reception ofthe audio information by primary wireless headphone 104 or secondarywireless headphone 106, such as ACK and NACK messages.

RF module 204 and physical layer module 206 may be in the same IC chipthat implements a short-range wireless communication protocol, such asthe BLUETOOTH protocol or WiFi protocol. RF module 204 may be configuredto modulate the audio information using the carrier wave at a frequency,for example, at 2.4 GHz for BLUETOOTH or WiFi communication, andtransmit the audio information at the frequency via antenna 202. RFmodule 204 may be further configured to receive and demodulate themessages and/or the audio information (e.g., the voice informationduring voice calls) from the carrier wave at the same frequency, forexample, at 2.4 GHz. Physical layer module 206 may be configured togenerate the physical link (baseband) between audio source 102 andprimary wireless headphone 104 (and secondary wireless headphone 106even though audio source 102 may not be aware of the connection withsecondary wireless headphone 106) according to the short-range wirelesscommunication protocol. For example, physical layer module 206 maygenerate baseband packets (e.g., BLUETOOTH packets) based on the musicand/or voice data (payload) and perform error correction using any knownmethods, such as forward error correction (FEC) and automatic repeatrequest (ARQ).

In some embodiments, the transmission of the audio information may occurat the audio data packet level in time slots. For example, according tothe standard BLUETOOTH protocol, the physical channel of the BLUETOOTHconnection is divided into time slots, each of which has the sameduration (e.g., 625 μs). RF module 204 in conjunction with antenna 202may transmit an audio data packet (N) in a time slot (N). Based on thereceptions of the audio data packet (N) in the time slot (N) at primarywireless headphone 104 and secondary wireless headphone 106, in thesubsequent time slot (N+1), RF module 204 in conjunction with antenna202 may receive a message from primary wireless headphone 104 orsecondary wireless headphone 106 alone, or messages from both primarywireless headphone 104 and secondary wireless headphone 106, which aregenerated in response to the reception status of the audio data packet(N) in the time slot (N). It is understood that additional components,although not shown in FIG. 2, may be included in audio source 102.

Primary wireless headphone 104 in this example may include a wirelesstransceiver (primary wireless transceiver) configured to receive theaudio information transmitted by audio source 102 and transmit orreceive error correcting messages (with or without an ECC) in responseto the reception of the audio information to audio source 102. Thewireless transceiver may be further configured to transmit thecommunication parameters to secondary wireless headphone 106. Primarywireless headphone 104 may include other components, such as anenclosure, speakers, and a microphone (not shown). Primary wirelesstransceiver may include an antenna 208, a first RF module 210, a secondRF module 212, a physical layer module 214, a MAC layer module 216, ahost controller interface (HCI) 218, and a control module 220. Some orall of the modules mentioned above may be integrated in the same IC chipto reduce the chip size and/or power consumption. Primary wirelessheadphone 104 may present at least part of the audio informationreceived from audio source 102 to the user via one of the user's ear.For example, the speaker of primary wireless headphone 104 may playmusic and/or voice based on the entire audio information or one audiochannel of the audio information.

Antenna 208 may include an array of conductors for transmitting andreceiving radio waves at two or more RF bands corresponding to first RFmodule 210 and second RF module 212. First RF module 210 may beconfigured to receive, from audio source 102, audio information andtransmit, to audio source 102, messages (e.g., ACK and NACK messages)via antenna 208. Second RF module 212 may be configured to transmit, tosecondary wireless headphone 106, the communication parameters and errorcorrecting messages (when primary wireless headphone 104 works as theECC transmitting headphone) via antenna 208. In some embodiments, secondRF module 212 may be further configured to receive, from secondarywireless headphone 106, error correcting messages (when primary wirelessheadphone 104 works as the ECC receiving headphone) via antenna 208.

In some embodiments, the first frequency used for the communicationsbetween audio source 102 and primary wireless headphone 104 is a “high”RF, such as 2.4 GHz used in BLUETOOTH or WiFi communication; the secondfrequency used for the communications between primary wireless headphone104 and secondary wireless headphone 106 is a “low” RF, such as between5 MHz and 50 MHz for NFMI communication. Both first RF module 210 andsecond RF module 212 may implement substantially the same short-rangewireless communication protocol for short-range wireless communicationsat different RF bands. For example, first RF module 210 may implement afirst short-range wireless communication protocol (e.g., the BLUETOOTHprotocol or WiFi protocol), and second RF module 212 may implement asecond short-range wireless communication protocol amended from thefirst short-range wireless communication protocol (e.g., the amendedBLUETOOTH or amended WiFi protocol). The second short-range wirelesscommunication protocol may be substantially the same as the firstshort-range wireless communication protocol except the carrier wavefrequency (and any specification related to the carrier wave frequency).

In some embodiments, first RF module 210 may operate at about 2.4 GHz(e.g., 2.4 GHz). In some embodiments, second RF module 212 may operatebetween about 5 MHz (e.g., 5 MHz) and about 50 MHz (e.g., 50 MHz) forNFMI communication. For example, second RF module 212 may operate atabout 10 MHz (e.g., 10 MHz). In some embodiments, second RF module 212may implement the frequency-hopping spread spectrum (FHSS) technique,such that the second frequency (low RF) may include a plurality offrequencies based on FHSS. For example, second RF module 212 mayimplement the amended BLUETOOTH protocol and use the FHSS specificationin the amended BLUETOOTH protocol. FHSS can further reduce signalinterference.

Physical layer module 214 may be configured to generate the physicallinks (baseband) between audio source 102 and primary wireless headphone104 according to the short-range wireless communication protocol and theamended short-range wireless communication protocol used by first RFmodule 210 and second RF module 212, respectively. For example, physicallayer module 214 may generate baseband packets (e.g., BLUETOOTH packets)based on the music and/or voice data (payload) and perform errorcorrection using any known methods, such as FEC and ARQ. MAC layermodule 216 may be configured to generate the logical data channel linksbetween audio source 102 and primary wireless headphone 104 according tothe short-range wireless communication protocol and between primarywireless headphone 104 and secondary wireless headphone 106 according tothe amended short-range wireless communication protocol used by first RFmodule 210 and second RF module 212, respectively. For example, MAClayer module 216 may generate link control channel, link managerchannel, user asynchronous channel, user isochronous channel, and usersynchronous channel based on the BLUETOOTH protocol (and the amendedBLUETOOTH protocol). HCI 218 may be configured to provide a commoninterface to physical layer module 214 and MAC layer module 216 andaccess to hardware status and control registers. For example, whenimplementing the BLUETOOTH protocol (and the amended BLUETOOTHprotocol), HCI 218 may provide a uniform method of accessing theBLUETOOTH baseband capabilities.

In some embodiments, the error correction messages are transmitted basedon a standard BLUETOOTH protocol in network layers above a physicallayer, for example, by MAC layer module 216 and HCI 218, and aretransmitted based on an amended BLUETOOTH protocol in the physicallayer, for example, by physical layer module 214. For example, the errorcorrecting messages can be transmitted at a higher symbol rate than thestandard BLUETOOTH protocol in the physical layer, for example, byphysical layer module 214 according to the amended BLUETOOTH protocol.In some embodiments, the symbol rate for transmitting the errorcorrecting messages in the physical layer is 2 M/s, which is higher thanthe standard BLUETOOTH symbol rate of 1 M/s. By increasing the symbolrate in the physical layer for the error correcting messages, more ECCscan be transmitted, thereby improving the error correction capability.

As described above, primary wireless headphone 104 can either an ECCtransmitting headphone or an ECC receiving headphone. In someembodiments, control module 220 may control primary wireless headphone104 to switch between the ECC transmitting headphone and the ECCreceiving headphone. In some embodiments, control module 220 maydetermine whether to switch the ECC headphone mode of primary wirelessheadphone 104 based on one or more parameters associated with primarywireless headphone 104 and/or secondary wireless headphone 106, such assignal quality. In one example, control module 220 may determine whetherthe signal quality (e.g., signal-to-noise ratio (SNR) or received signalstrength indicator (RSSI)) is above a threshold and cause primarywireless headphone 104 to switch to a different ECC headphone mode. Thatis, in some embodiments, the wireless headphone with the relatively poorsignal quality may be used as the ECC transmitting headphone, while thewireless headphone with the relatively good signal quality may be usedas the ECC receiving headphone, so that the ACK/NACK messagestransmitted by the ECC receiving headphone can be more easily receivedby audio source 102. In some embodiments, the wireless headphone withthe relatively poor signal quality may be used as the ECC receivingheadphone, while the wireless headphone with the relatively good signalquality may be used as the ECC transmitting headphone, so that moreerror correcting messages with ECCs can be generated to reduce the timesof re-transmission.

Control module 220 may be further configured to control the generationof the ECC based on the successfully received audio information whenprimary wireless headphone 104 is working as an ECC transmittingheadphone or control the correction of the audio information based onthe received ECC when primary wireless headphone 104 is working as anECC receiving headphone. When working as the ECC receiving headphone,control module 220 may be further configured to determine whether totransmit an ACK message or a NACK message to audio source 102 dependingon various factors, including (1) whether an error correcting message isreceived from secondary wireless headphone 106 (the ECC transmittingheadphone), (2) whether the received error correcting message includesan ECC, (3) whether the audio information received by primary wirelessheadphone 104 needs correction, and (4) whether the correction of theaudio information based on the ECC is successful.

Secondary wireless headphone 106 in this example may include a wirelesstransceiver (secondary wireless transceiver) configured to receive(snoop) the audio information transmitted by audio source 102 andtransmit or receive error correcting messages (with or without an ECC)in response to the reception of the audio information to audio source102. The wireless transceiver may be further configured to receive thecommunication parameters from primary wireless headphone 104. Secondarywireless headphone 106 may include other components, such as anenclosure, speakers, and a microphone (not shown). Secondary wirelesstransceiver may include an antenna 222, a first RF module 224, a secondRF module 226, a physical layer module 228, a MAC layer module 230, anHCI 232, and a control module 234. Some or all of the modules mentionedabove may be integrated in the same IC chip to reduce the chip sizeand/or power consumption. Secondary wireless headphone 106 may presentat least part of the audio information to the user via one of the user'sear. For example, the speaker of secondary wireless headphone 106 mayplay music and/or voice based on the audio information or one audiochannel of the audio information.

In this example, secondary wireless headphone 106 has the same hardwarestructures as primary wireless headphone 104. The functions of eachmodule mentioned above in secondary wireless headphone 106 are the sameas the counterparts in primary wireless headphone 104 and thus, will notbe repeated. Different from primary wireless headphone 104, secondarywireless headphone 106 in this example works in the snoop mode, so thataudio source 102 may not recognize the connection with secondarywireless headphone 106. To enable secondary wireless headphone 106 towork in the snoop mode, in some embodiments, second RF module 212 ofprimary wireless headphone 104 may transmit, to second RF module 226 ofsecondary wireless headphone 106, one or more communication parametersassociated with the short-range wireless communication protocol usedbetween audio source 102 and primary wireless headphone 104. Thecommunication parameters may include any parameters necessary forenabling secondary wireless headphone 106 to snoop the communicationsbetween audio source 102 and primary wireless headphone 104, such as theaddress of audio source 102 (e.g., the IP address or MAC address) andthe encryption parameters used between audio source 102 and primarywireless headphone 104.

As described above, similar to control module 220 of primary wirelessheadphone 104, control module 234 of secondary wireless headphone 106may control secondary wireless headphone 106 to switch between the ECCtransmitting headphone and the ECC receiving headphone. The switch maybe determined based on one or more parameters, such as the relativesignal quality between primary wireless headphone 104 and secondarywireless headphone 106. For example, both control modules 220 and 234may work together to switch the ECC headphone modes of primary wirelessheadphone 104 and secondary wireless headphone 106 to improve theoverall performance of the pair of wireless headphones 104 and 106 asdescribed above in detail.

Control module 234 may be further configured to control the generationof the ECC based on the successfully received audio information whensecondary wireless headphone 106 is working as an ECC transmittingheadphone or control the correction of the audio information based onthe received ECC when secondary wireless headphone 106 is working as anECC receiving headphone. When working as the ECC receiving headphone,control module 234 may be further configured to determine whether totransmit an ACK message or a NACK message to audio source 102 dependingon various factors, including (1) whether an error correcting message isreceived from primary wireless headphone 104 (the ECC transmittingheadphone), (2) whether the received error correcting message includesan ECC, (3) whether the audio information received by secondary wirelessheadphone 106 needs correction, and (4) whether the correction of theaudio information based on the ECC is successful.

Although in FIG. 2, the same physical layer module, MAC layer module,and HCI are used for both first and second RF modules 210 and 212 or 224and 226, it is understood that in some embodiments, each of first andsecond RF modules 210 and 212 or 224 and 226 may have its own physicallayer module, MAC layer module, and/or HCI. In other words, each ofprimary and secondary wireless headphones 104 and 106 may include twophysical layer modules, two MAC layer modules, and/or two HCIs. As aresult, two different types of short-range wireless communications canbe implemented by each of primary and secondary wireless headphones 104and 106. In some embodiments, second RF modules 212 and 226 and theirrespective physical layer modules, MAC layers modules, and/or HCIs areused to implement WiFi communication or NFMI communication betweenprimary and secondary wireless headphones 104 and 106 for transmittingand receiving error correcting messages.

FIG. 3 is a block diagram illustrating exemplary wireless headphone 104or 106 in accordance with an embodiment. In this example, each ofprimary wireless headphone 104 and secondary wireless headphone 106includes an RF front-end 302, an analog-to-digital (A/D) converter 304,a demodulation module 306, a clock frequency module 308, a phase-lockedloop (PLL) 310, a clock oscillator 312, a frequency divider 314, and atiming module 316. RF front-end 302 may be operatively coupled to anantenna and configured to receive the RF signals, such as audio signalsrepresenting the audio information described above in detail. RFfront-end 302 may include an antenna switch, low-noise amplifier (LNA),power amplifier (PA), filter, etc. A/D converter 304 may be operativelycoupled to RF front-end 302 and configured to convert an audio signalfrom an analog signal to a digital signal and provide the digital audiosignal to demodulation module 306 that is operatively coupled to A/Dconverter 304. The A/D conversion may be performed by A/D converter 304based on an A/D sampling rate determined by frequency divider 314.

In some embodiments, primary wireless headphone 104 and secondarywireless headphone 106 may not communicate directly except fortransmitting the communication parameters and error correction messagesas describe above. Primary wireless headphone 104 and secondary wirelessheadphone 106 may be synchronized via their communications with audiosource 102. The local clocks of each of primary wireless headphone 104and secondary wireless headphone 106 may be synchronized with the remoteclock of audio source 102 and thus, are synchronized with one another.By indirectly synchronizing primary wireless headphone 104 and secondarywireless headphone 106 via audio source 102, the sound can besimultaneously played by both primary wireless headphone 104 andsecondary wireless headphone 106. One example of indirectlysynchronizing primary wireless headphone 104 and secondary wirelessheadphone 106 via audio source 102 is disclosed in corresponding U.S.patent application Ser. No. 15/939,258, having a title “SYNCHRONIZATIONOF WIRELESS HEADPHONES,” which is incorporated herein by reference.

FIGS. 4A-4E are timing diagrams of exemplary wireless audio systems inaccordance with various embodiments. As described above, errorcorrecting messages may be transmitted from an ECC transmittingheadphone to an ECC receiving headphone. As described above, in someembodiments, each of the time slots (e.g., N and N+1) has the sameduration, for example, 625 μs for BLUETOOTH communication. As shown inFIG. 4A, in a first time slot (N), the audio source transmits an audiodata packet (e.g., a BLUETOOTH audio data packet), and each of the ECCtransmitting and receiving headphones receives the audio data packet. Inthe same time slot (N), the ECC transmitting headphone transmits anerror correcting message including an ECC or a pseudo error correctingmessage without an ECC depending on whether the ECC transmittingheadphone successfully receives the audio data packet in time slot (N).In the same time slot (N), the ECC receiving headphone receives theerror correcting message or pseudo error correcting message from the ECCtransmitting headphone.

In a second time slot (N+1) immediately subsequent to the first timeslot (N), the ECC receiving headphone may transmit an ACK message or aNACK message to the audio source depending on whether it successfullyreceives the audio data packet based on the error correcting message inthe first time slot (N). In a first situation, if in the first time slot(N), the ECC receiving headphone receives the error correcting messageincluding the ECC from the ECC transmitting headphone and corrects theerror in the audio data packet based on the ECC (i.e., successfullyreceiving the audio data packet after the correction), then in thesecond time slot (N+1), the ECC receiving headphone transmits an ACKmessage to the audio source. In a second situation, if in the first timeslot (N), the ECC receiving headphone receives the error correctingmessage including the ECC from the ECC transmitting headphone and doesnot find any error in the audio data packet (i.e., successfullyreceiving the audio data packet without the correction), then in thesecond time slot (N+1), the ECC receiving headphone transmits an ACKmessage to the audio source as well. In a third situation, if in thefirst time slot (N), the ECC receiving headphone receives the errorcorrecting message including the ECC from the ECC transmitting headphoneand fails to correct the error in the audio data packet using the ECC(i.e., not successfully receiving the audio data packet), then in thesecond time slot (N+1), the ECC receiving headphone transmits a NACKmessage to the audio source. In a fourth situation, if in the first timeslot (N), the ECC receiving headphone receives the pseudo errorcorrecting message without the ECC from the ECC transmitting headphoneor does not receive any error correcting message (i.e., not successfullyreceiving the error correcting message including the ECC), then in thesecond time slot (N+1), the ECC receiving headphone transmits a NACKmessage to the audio source as well.

In some embodiments, if in the first time slot (N), the ECC transmittingheadphone does not successfully receive the audio data packet from theaudio source, then in the second time slot (N+1), the ECC transmittingheadphone transmits an ACK message to the audio source as well. FIG. 5is a depiction of an exemplary header of an ACK or NACK message inaccordance with an embodiment. The header includes an acknowledgeindication bit (ARQN) indicative of whether the packet is an ACK messageor a NACK message. The packet is an ACK message if ARQN is 1, as shownin FIG. 5. The packet is a NACK message if ARQN is 0.

It is understood that in FIG. 4A, each audio data packet in transmittedwithin a single time slot, e.g., the first time slot (N), for exampleaccording to BLUETOOTH Hands Free Profile (HFP). In the time slot inwhich the audio data packet is transmitted by the audio source, theaudio data packet and the error correcting message can share the sametime slot. For example, the audio data packet may be transmitted priorto the error correcting message in the same time slot. In someembodiments, each audio data packet can be transmitted within multipletime slots, for example according to BLUETOOTH A2DP. As shown in FIG.4B, the audio data packet is transmitted from the audio source to eachof the ECC transmitting and receiving headphones in N slots, and theerror correcting message or pseudo error correcting message istransmitted from the ECC transmitting headphone to the ECC receivingheadphone at the end of the last one of N slots (Nth slot). That is, atleast part of the audio data packet is transmitted in the same slot (Nthslot) as the error correcting message. Similar to the example in FIG.4A, in a time slot immediately subsequent to the last one of N slots,e.g., (N+1)th slot, the ECC receiving headphone transmits an ACK messageor a NACK message to the audio source as described above in detail.

It is further understood that in some embodiments, the error correctingmessage may be transmitted in more than one time slot. In the case inwhich the audio data packet and the error correcting message aretransmitted in N time slots (e.g., 3 or 5 time slots), the specificnumbers of time slots within the N time slots used for transmitting therespective audio data packet and the error correcting message are notlimited as long as the audio data packet is transmitted prior to theerror correcting message in the N time slots. Thus, the error correctingmessage may be transmitted in the in the last one or more time slots ofthe N time slots.

In some embodiments, another type of error correcting message without anECC may be transmitted from the ECC transmitting headphone to the ECCreceiving headphone when the ECC transmitting headphone successfullyreceives the header of the audio data packet but fails to receive thepayload of the audio data packet. FIGS. 5A and 5B are depictions ofexemplary BLUETOOTH audio data packets in accordance with an embodiment.Both BLUETOOTH audio data packets in FIGS. 5A and 5B include an accesscode, a header, and a payload in which the actual audio information iscoded. As described above, FIG. 6 illustrates an example of a header ina BLUETOOTH audio data packet. FIG. 5B illustrates an enhanced data rateBLUETOOTH audio data packet, which further includes guard,synchronization, and trailer fields. The payload of the enhanced datarate BLUETOOTH audio data packet may be transmitted at a higher symbolrate than the standard BLUETOOTH symbol rate by using differentmodulation technique (DPSK) than the header (GFSK). As described above,the ECC can be coded based on the actual audio information in thepayload of a BLUETOOTH audio data packet using RS code, BCH code, etc.

As shown in FIG. 4C, in a first time slot (N), if the ECC transmittingsuccessfully receives the header of the audio data packet but fails toreceive the payload of the audio data packet, it transmits a first errorcorrecting message without an ECC to the ECC receiving headphone. In thesecond time slot (N+1) immediate subsequent to the first time slot (N),the ECC receiving headphone transmits a second error correcting messageincluding an ECC generated by coding the payload of the audio datapacket received by the ECC receiving headphone in the first time lot(N). By receiving the second error correcting message including the ECC,in the second time slot (N+1), the ECC transmitting headphone maycorrect the errors in the payload of the audio data packet. Similar tothe example in FIG. 4A, in the second time slot (N+1), the ECC receivingheadphone transmits an ACK message or a NACK message to the audio sourceas described above in detail. It is understood that although FIG. 4Cshows the transmission of an audio data packet in a single time slot,the scheme can be expanded to situations in which the audio data packetis transmitted over multiple time slots, for example according toBLUETOOTH A2DP as described above with respect to FIG. 4B.

FIGS. 4D and 4E are timing diagrams of an exemplary wireless audiosystem implemented in another schedule. In this example, the ECCtransmitting headphone, as opposed to the ECC receiving headphone,transmits the ACK or NACK message to the audio source. As shown in FIG.4D, in the first time slot (N), the ECC transmitting headphonesuccessfully receives the audio data packet and thus, transmits an errorcorrecting message including an ECC in the same time slot (N) to the ECCreceiving headphone. In the same time slot (N), the ECC receivingheadphone transmits a status message (STAT) to the ECC transmittingheadphone, which indicates whether the ECC receiving headphonesuccessfully receives the audio data packet based on the ECC receivedfrom the ECC transmitting headphone. For example, the status message mayindicate that the reception of the audio data packet at the ECCreceiving headphone is successfully either because no error is found atthe first place or the error has been corrected using the ECC. Thestatus message may indicate that reception of the audio data packet atthe ECC receiving headphone is unsuccessfully even after the correctionusing the ECC. In the immediately subsequent slot (N+1), the ECCtransmitting headphone transmits an ACK message or a NACK message to theaudio source based on the status message received from the ECC receivingheadphone.

As shown in FIG. 4E, in the first time slot (N), the ECC transmittingheadphone does not successfully receive the audio data packet and thus,transmits a status message indicative of such failure to the ECCreceiving headphone. In the same time slot (N), the ECC receivingheadphone may transmit an error correcting message including an ECC ifit successfully receives the audio data packet or a status messageindicative of its failure to successfully receive the audio data packetto the ECC transmitting headphone. If the ECC transmitting headphonereceives the error correcting message including the ECC from the ECCreceiving headphone in the first time slot (N) and corrects the audiodata packet based on the ECC, then in the immediate subsequent time slot(N+1), the ECC transmitting headphone transmits an ACK message to theaudio source. If the ECC transmitting headphone receives the errorcorrecting message including the ECC but fails to correct the audio datapacket based on the ECC or if the ECC transmitting headphone receivesthe status message indicative of the ECC receiving headphone's failureto successfully receive the audio data packet, then in the immediatesubsequent time slot (N+1), the ECC transmitting headphone transmits aNACK message to the audio source.

It is understood that although FIGS. 4D and 4E show the transmission ofan audio data packet in a single time slot, the scheme can be expandedto situations in which the audio data packet is transmitted overmultiple time slots, for example according to BLUETOOTH A2DP asdescribed above with respect to FIG. 4B. In some embodiments, each timeslot may be a standard BLUETOOTH time slot having the same duration(e.g., 625 μs), and the messages described in FIGS. 4D and 4E arecommunicated using WiFi communication such that multiple messages can becommunicated in a single standard BLUETOOTH time slot.

FIG. 7 is a flow chart illustrating an exemplary method 700 forwirelessly communicating audio information in accordance with anembodiment. Method 700 can be performed by processing logic that cancomprise hardware (e.g., circuitry, dedicated logic, programmable logic,microcode, etc.), software (e.g., instructions executing on a processingdevice), or a combination thereof. It is to be appreciated that not alloperations may be needed to perform the disclosure provided herein.Further, some of the operations may be performed simultaneously, or in adifferent order than shown in FIG. 7, as will be understood by a personof ordinary skill in the art.

Method 700 shall be described with reference to FIGS. 1A, 1B, and 2.However, method 700 is not limited to that exemplary embodiment.Starting at 702, a first type of short-range wireless communication,such as BLUETOOTH communication, is established with an audio source. Insome embodiments, the short-range wireless communication is establishedbetween primary wireless headphone 104 and audio source 102. At 704,communication parameters indicative of the short-range wirelesscommunication are transmitted. In some embodiments, the communicationparameters are transmitted from primary wireless headphone 104 tosecondary wireless headphone 106 using the first type of short-rangewireless communication, such as BLUETOOTH communication, or a secondtype of short-range wireless communication, such as WiFi communicationor NFMI communication.

At 706, audio information is received by an ECC transmitting headphonefrom the audio source using the first type of short-range wirelesscommunication, such as BLUETOOTH communication. In some embodiments, theECC transmitting headphone is primary wireless headphone 104, and theaudio information is received by primary wireless headphone 104 via thenormal communication link. In some embodiments, the ECC transmittingheadphone is secondary wireless headphone 106, and the audio informationis snooped by secondary wireless headphone 106 via the snoopcommunication link.

At 708, an ECC is generated by the ECC transmitting headphone based onthe audio information received by the ECC transmitting headphone inresponse to successfully receiving the audio information. The audioinformation may include a BLUETOOTH audio data packet, and the errorcorrecting code may be generated by coding a payload of the BLUETOOTHaudio data packet. In some embodiments, control module 220 of primarywireless headphone 104 controls the coding of the payload when primarywireless headphone 104 is the ECC transmitting headphone. In someembodiments, control module 234 of secondary wireless headphone 106controls the coding of the payload when secondary wireless headphone 106is the ECC transmitting headphone.

At 710, an error correcting message including the ECC is transmitted bythe ECC transmitting headphone. The error correcting message may betransmitted based on a standard BLUETOOTH protocol in network layersabove a physical layer and transmitted at a higher symbol rate than thestandard BLUETOOTH protocol in the physical layer. The error correctingmessage may be transmitted using a second type of short-range wirelesscommunication different from the first type of short-range wirelesscommunication for transmitting the audio information. For example, thefirst type of short-range wireless communication is BLUETOOTHcommunication, and the second type of short-range wireless communicationis WiFi communication or NFMI communication. In one example, a BLUETOOTHaudio data packet and the error correcting message are transmitted inthe same time slot subsequently. In another example, a BLUETOOTH audiodata packet is transmitted over multiple time slots, and the errorcorrecting message is transmitted at the end of the last one or more ofthe multiple time slots. In some embodiments, second RF module 212 ofprimary wireless headphone 104 transmits the error correcting messagewhen primary wireless headphone 104 is the ECC transmitting headphone.In some embodiments, second RF module 226 of secondary wirelessheadphone 106 transmits the error correcting message when secondarywireless headphone 106 is the ECC transmitting headphone.

At 712, the audio information is received by the ECC receiving headphonefrom the audio source using the first type of short-range wirelesscommunication, such as BLUETOOTH communication. In some embodiments, theECC receiving headphone is primary wireless headphone 104, and the audioinformation is received by primary wireless headphone 104 via the normalcommunication link. In some embodiments, the ECC receiving headphone issecondary wireless headphone 106, and the audio information is snoopedby secondary wireless headphone 106 via the snoop communication link.

At 714, the error message including the ECC is received by the ECCreceiving headphone from the ECC transmitting headphone, for example,using the first type of short-range wireless communication, such as WiFicommunication or NFMI communication. In some embodiments, the audioinformation received from the audio source at 712 is corrected based onthe error correcting code by the ECC receiving headphone if the ECCreceiving headphones detect error(s) in the audio information. The ECCreceiving headphone then can successfully receive the audio informationafter the correction. In some embodiments, second RF module 212 ofprimary wireless headphone 104 receives the error correcting messagewhen primary wireless headphone 104 is the ECC receiving headphone. Insome embodiments, second RF module 226 of secondary wireless headphone106 receives the error correcting message when secondary wirelessheadphone 106 is the ECC receiving headphone.

At 716, in response to successfully receiving the audio information fromthe audio source based on the error correcting code, an ACK message istransmitted to the audio source by the ECC receiving headphone. The ACKmessage may be transmitted in a time slot that is immediately subsequentto the time slot in which the error correcting message is transmittedand received. In some embodiments, first RF module 210 of primarywireless headphone 104 transmits the ACK message when primary wirelessheadphone 104 is the ECC receiving headphone. In some embodiments, firstRF module 224 of secondary wireless headphone 106 transmits the ACKmessage when secondary wireless headphone 106 is the ECC receivingheadphone.

FIG. 8 is a flow chart illustrating another exemplary method 800 forwirelessly communicating audio information in accordance with anembodiment. Method 800 can be performed by processing logic that cancomprise hardware (e.g., circuitry, dedicated logic, programmable logic,microcode, etc.), software (e.g., instructions executing on a processingdevice), or a combination thereof. It is to be appreciated that not alloperations may be needed to perform the disclosure provided herein.Further, some of the operations may be performed simultaneously, or in adifferent order than shown in FIG. 8, as will be understood by a personof ordinary skill in the art.

Method 800 may be performed by an ECC transmitting headphone disclosedherein regardless of whether it is primary wireless headphone 104 orsecondary wireless headphone 106. Starting at 802, the ECC transmittingheadphone receives a BLUETOOTH audio data packet from an audio sourceusing BLUETOOTH communication in one or more time slots. At 804, the ECCtransmitting headphone determines whether the BLUETOOTH audio datapacket is successfully received. If the answer is yes, method 800proceeds to 806 at which the ECC transmitting headphone generates an ECCby coding the payload of the BLUETOOTH audio data packet. At 808, theECC transmitting headphone transmits an error correcting messageincluding the ECC to an ECC receiving headphone in the last time slot inwhich the BLUETOOTH audio data packet is received. If the answer at 804is no, method 800 proceeds to 810 at which the ECC transmittingheadphone transmits a NACK message to the audio source. Alternatively oradditionally, at 812, the ECC transmitting headphone transmits a pseudoerror correcting message without the ECC to the ECC receiving headphone.

FIG. 9 is a flow chart illustrating still another exemplary method 900for wirelessly communicating audio information in accordance with anembodiment. Method 900 can be performed by processing logic that cancomprise hardware (e.g., circuitry, dedicated logic, programmable logic,microcode, etc.), software (e.g., instructions executing on a processingdevice), or a combination thereof. It is to be appreciated that not alloperations may be needed to perform the disclosure provided herein.Further, some of the operations may be performed simultaneously, or in adifferent order than shown in FIG. 9, as will be understood by a personof ordinary skill in the art.

Method 900 may be performed by an ECC receiving headphone disclosedherein regardless of whether it is primary wireless headphone 104 orsecondary wireless headphone 106. Starting at 902, the ECC receivingheadphone receives a BLUETOOTH audio data packet from an audio sourceusing Bluetooth communication in one or more time slots. At 904, the ECCreceiving headphone receives an error correcting message including anECC in the last time slot in which the BLUETOOTH audio data packet isreceived. At 906, the ECC receiving headphone determines whether theerror correcting message including the ECC is successfully received. Ifthe answer is yes, method 900 proceeds to 908 at which the ECC receivingheadphone determines whether the BLUETOOTH audio data packet needs to becorrected (e.g., containing errors in the payload). If the answer isyes, at 910, the ECC receiving headphone corrects the BLUETOOTH audiodata packet based on the ECC. If the answer is no at 908, method 900proceeds to 912 directly at which the ECC receiving headphone determineswhether the BLUETOOTH audio data packet is successfully received. It isunderstood that the answer at 912 can be yes either when the BLUETOOTHaudio data packet needs to be corrected at 908 and is corrected after910 or can be yes when the BLUETOOTH audio data packet does not need tobe corrected at 908. Nevertheless, at 914, the ECC receiving headphonetransmits an ACK message to the audio source in a time slot immediatelysubsequent to the time slot in which the error correcting message isreceived when the answer at 912 is yes. Otherwise, method 900 proceedsto 916 at which the ECC receiving headphone transmits a NACK message tothe audio source in the immediately subsequent time slot. Also, if theanswer at 906 is no, i.e., the ECC receiving headphone does notsuccessfully receive the error correcting message including the ECC fromthe ECC transmitting headphone (e.g., not receiving any error correctingmessage at all or receiving a pseudo error correcting message without anECC), method 900 proceeds to 916 directly at which the ECC receivingheadphone transmits the NACK message to the audio source.

FIG. 10 is a flow chart illustrating yet another exemplary method 1000for wirelessly communicating audio information in accordance with anembodiment. Method 1000 can be performed by processing logic that cancomprise hardware (e.g., circuitry, dedicated logic, programmable logic,microcode, etc.), software (e.g., instructions executing on a processingdevice), or a combination thereof. It is to be appreciated that not alloperations may be needed to perform the disclosure provided herein.Further, some of the operations may be performed simultaneously, or in adifferent order than shown in FIG. 10, as will be understood by a personof ordinary skill in the art.

Method 1000 may be performed by an ECC transmitting headphone disclosedherein regardless of whether it is primary wireless headphone 104 orsecondary wireless headphone 106. Method 800 may be implemented for theexamples disclosed in FIGS. 1C, 1D, and 4C. Starting at 1002, the ECCtransmitting headphone receives a BLUETOOTH audio data packet from anaudio source using BLUETOOTH communication in one or more time slots. At1004, the ECC transmitting headphone determines whether the payload ofthe BLUETOOTH audio data packet is successfully received. If the answeris yes, method 1000 proceeds to 1006 at which the ECC transmittingheadphone generates a first ECC by coding the payload of the BLUETOOTHaudio data packet. At 1008, the ECC transmitting headphone transmits afirst error correcting message including the first ECC to an ECCreceiving headphone in the last one or more time slots in which theBLUETOOTH audio data packet is received. If the answer at 1004 is no,method 1000 proceeds to 1010 at which the ECC transmitting headphonedetermines whether the header of the BLUETOOTH audio data packet issuccessfully received. If the answer at 1010 is yes, method 1000proceeds to 1012 at which a second error correcting message without thefirst ECC is transmitted to the ECC receiving headphone in the last oneor more time slots in which the BLUETOOTH audio data packet is received.

In some cases, method 1000 may proceed to 1014 at which the ECCtransmitting headphone receives a third error correcting messageincluding a second ECC from the ECC receiving headphone in theimmediately subsequent time slot. The second ECC may be generated bycoding the payload of the BLUETOOTH audio data packet that issuccessfully received by the ECC receiving headphone in the same one ormore time slots in which the ECC transmitting headphone receives theBLUETOOTH audio data packet. In some embodiments, the header may betransmitted with the second error correcting message from the ECCtransmitting headphone to the ECC receiving headphone to match theBLUETOOTH audio data packets received by the ECC transmitting andreceiving headphones, respectively. At 1016, the ECC transmittingheadphone may correct the payload of the BLUETOOTH audio data packetbased on the second ECC generated by the ECC receiving headphone.Optionally, if the answer at 1010 is no, i.e., the ECC transmittingheadphone successfully receives neither the payload nor the header ofthe BLUETOOTH audio data packet, at 1018, the ECC transmitting headphonetransmits a NACK message to the audio source.

FIG. 11 is a flow chart illustrating yet another exemplary method 1100for wirelessly communicating audio information in accordance with anembodiment. Method 1100 can be performed by processing logic that cancomprise hardware (e.g., circuitry, dedicated logic, programmable logic,microcode, etc.), software (e.g., instructions executing on a processingdevice), or a combination thereof. It is to be appreciated that not alloperations may be needed to perform the disclosure provided herein.Further, some of the operations may be performed simultaneously, or in adifferent order than shown in FIG. 11, as will be understood by a personof ordinary skill in the art.

Method 1100 may be performed by an ECC receiving headphone disclosedherein regardless of whether it is primary wireless headphone 104 orsecondary wireless headphone 106. Method 1100 may be implemented for theexamples disclosed in FIGS. 1C, 1D, and 4C. Starting at 1102, the ECCreceiving headphone receives a BLUETOOTH audio data packet from an audiosource using BLUETOOTH communication in one or more time slots. At 1104,the ECC receiving headphone receives an error correcting message in thelast one or more time slots in which the BLUETOOTH audio data packet isreceived. At 1106, the ECC receiving headphone determines whether thereceived error correcting message is the first error correcting messageincluding the first ECC. If the answer is yes, method 1100 proceeds to1109 at which the ECC receiving headphone determines whether theBLUETOOTH audio data packet needs to be corrected. If the answer at 1108is yes, method 1100 proceeds to 1110 at which the ECC receivingheadphone corrects the BLUETOOTH audio data packet based on the firstECC. At 1112, the ECC receiving headphone determines whether theBLUETOOTH audio data packet is successfully received either directlyafter 1108 without correction or after the correction at 1110. If theanswer at 1112 is yes, method proceeds to 1114 at which the ECCreceiving headphone transmits an ACK message to the audio source in theimmediately subsequent time slot. Otherwise, method proceeds to 1122 atwhich the ECC receiving headphone transmits a NACK message to the audiosource in the immediately subsequent time slot.

Back to 1106, if the answer is no, the ECC receiving headphonedetermines whether the received error correcting message is the seconderror correcting message without the first ECC, which indicates that theECC transmitting headphone successfully receives the header of theBLUETOOTH audio data packet but not the payload. If the answer at 1116is yes, the ECC receiving headphone generates the second ECC by codingthe payload of the BLUETOOTH audio data packet successfully received at1118. In some embodiments, the header may be transmitted with the seconderror correcting message from the ECC transmitting headphone to the ECCreceiving headphone to match the BLUETOOTH audio data packets receivedby the ECC transmitting and receiving headphones, respectively. At 1120,the ECC receiving headphone transmits a third error correcting messageincluding the second ECC to the ECC transmitting headphone in theimmediately subsequent time slot. Also, if the answer at 1116 is no,i.e., the ECC receiving headphone receives neither the first errorcorrecting message nor the second error correcting message, method 1116proceeds to 1122 directly at which the ECC receiving headphone transmitsthe NACK message to the audio source in the immediately subsequent timeslot.

It is understood that all the error correcting messages disclosed hereinmay be replaced with the actual audio information, e.g., the payload ofthe audio data packet without coding, in some embodiments. In otherwords, instead of generating the ECC by coding the payload of an audiodata packet and transmitting an error correcting message including theECC, the ECC transmitting headphone may transmit a message including thepayload of the audio data packet without ECC coding.

It is to be appreciated that the Detailed Description section, and notthe Summary and Abstract sections, is intended to be used to interpretthe claims. The Summary and Abstract sections may set forth one or morebut not all exemplary embodiments of the present disclosure ascontemplated by the inventor(s), and thus, are not intended to limit thepresent disclosure or the appended claims in any way.

While the present disclosure has been described herein with reference toexemplary embodiments for exemplary fields and applications, it shouldbe understood that the present disclosure is not limited thereto. Otherembodiments and modifications thereto are possible, and are within thescope and spirit of the present disclosure. For example, and withoutlimiting the generality of this paragraph, embodiments are not limitedto the software, hardware, firmware, and/or entities illustrated in thefigures and/or described herein. Further, embodiments (whether or notexplicitly described herein) have significant utility to fields andapplications beyond the examples described herein.

Embodiments have been described herein with the aid of functionalbuilding blocks illustrating the implementation of specified functionsand relationships thereof. The boundaries of these functional buildingblocks have been arbitrarily defined herein for the convenience of thedescription. Alternate boundaries can be defined as long as thespecified functions and relationships (or equivalents thereof) areappropriately performed. Also, alternative embodiments may performfunctional blocks, steps, operations, methods, etc. using orderingsdifferent than those described herein.

The breadth and scope of the present disclosure should not be limited byany of the above-described exemplary embodiments, but should be definedonly in accordance with the following claims and their equivalents.

What is claimed is:
 1. A wireless audio system, comprising: a firstwireless headphone configured to: receive, from an audio source, audioinformation using a first type of short-range wireless communication; inresponse to successfully receiving the audio information from the audiosource, generate an error correcting code based on the audioinformation; and transmit an error correcting message including theerror correcting code without transmitting the audio information; and asecond wireless headphone configured to: receive, only from the audiosource, the audio information using the first type of short-rangewireless communication; receive, from the first wireless headphone, theerror correcting message including the error correcting code; and inresponse to successfully receiving the audio information from the audiosource based on the error correcting code, transmit an acknowledgement(ACK) message to the audio source, wherein one of the first and secondwireless headphones works in a snoop mode to communicate with the audiosource based on communication parameters of another one of the first andsecond wireless headphones.
 2. The wireless audio system of claim 1,wherein the second wireless headphone is further configured to, inresponse to at least one of (i) not successfully receiving the audioinformation from the audio source, or (ii) not successfully receivingthe error correcting message including the error correcting code fromthe first wireless headphone, transmit a negative acknowledgement (NACK)message to the audio source.
 3. The wireless audio system of claim 1,wherein: the first wireless headphone is further configured to, inresponse to not successfully receiving the audio information from theaudio source, transmit a first NACK message to the audio source; and thesecond wireless headphone is further configured to, in response to notsuccessfully receiving the audio information from the audio source,transmit a second NACK message to the audio source.
 4. The wirelessaudio system of claim 1, wherein: the audio information includes aBLUETOOTH audio data packet; and the error correcting code is generatedby coding a payload of the BLUETOOTH audio data packet.
 5. The wirelessaudio system of claim 4, wherein the error correcting message istransmitted based on a standard BLUETOOTH protocol in network layersabove a physical layer.
 6. The wireless audio system of claim 5, whereinthe error correcting message is transmitted at a higher symbol rate thanthe standard BLUETOOTH protocol in the physical layer.
 7. The wirelessaudio system of claim 1, wherein the first wireless headphone is furtherconfigured to, in response to not successfully receiving the audioinformation from the audio source, transmit a pseudo error correctingmessage without the error correcting code to the second wirelessheadphone.
 8. The wireless audio system of claim 1, wherein the secondwireless headphone is further configured to: correct the audioinformation from the audio source based on the error correcting code;and successfully receive the audio information after the correction. 9.The wireless audio system of claim 1, wherein the first wirelessheadphone is in the snoop mode, and the second wireless headphone isfurther configured to: establish the first type of short-range wirelesscommunication with the audio source; and transmit, to the first wirelessheadphone, the communication parameters indicative of the first type ofshort-range wireless communication between the second wireless headphoneand the audio source.
 10. The wireless audio system of claim 1, whereinthe second wireless headphone is in the snoop mode, and the firstwireless headphone is further configured to: establish the first type ofshort-range wireless communication with the audio source; and transmit,to the second wireless headphone, the communication parametersindicative of the first type of short-range wireless communicationbetween the first wireless headphone and the audio source.
 11. Thewireless audio system of claim 1, wherein the first and second wirelessheadphones are configured to be dynamically switched based on a signalquality of each of the first and second wireless headphones.
 12. Thewireless audio system of claim 1, wherein a signal quality of the firstwireless headphone is better than a signal quality of the secondwireless headphone.
 13. The wireless audio system of claim 1, wherein asignal quality of the second wireless headphone is better than a signalquality of the first wireless headphone.
 14. The wireless audio systemof claim 1, wherein: the first type of short-range wirelesscommunication is based on a plurality of slots with a same duration; thefirst wireless headphone is configured to receive at least part of theaudio information and transmit the error correcting message in a sameslot; and the second wireless headphone is configured to transmit theACK message in an immediately subsequent slot.
 15. The wireless audiosystem of claim 1, wherein the first wireless headphone is configured totransmit the error correcting message to the second wireless headphoneusing a second type of short-range wireless communication different fromthe first type of short-range wireless communication.
 16. The wirelessaudio system of claim 15, wherein the first type of short-range wirelesscommunication is BLUETOOTH communication, and the second type ofshort-range wireless communication is WiFi communication or near-fieldmagnetic induction (NFMI) communication.
 17. A method for wirelesslycommunicating audio information, comprising: receiving, by a firstwireless headphone, audio information from an audio source using a firsttype of short-range wireless communication; in response to successfullyreceiving the audio information from the audio source, generating, bythe first wireless headphone, an error correcting code based on theaudio information; transmitting, by the first wireless headphone, anerror correcting message including the error correcting code withouttransmitting the audio information; receiving, by a second wirelessheadphone, the audio information only from the audio source using thefirst type of short-range wireless communication; receiving, by thesecond wireless headphone, the error correcting message including theerror correcting code from the first wireless headphone; and in responseto successfully receiving the audio information from the audio sourcebased on the error correcting code, transmitting, by the second wirelessheadphone, an ACK message to the audio source.
 18. The method of claim17, further comprising: establishing, by the first wireless headphone,the first type of short-range wireless communication with the audiosource; and transmitting, by the first wireless headphone, communicationparameters indicative of the first type of short-range wirelesscommunication to the second wireless headphone, wherein receiving, bythe second wireless headphone, the audio information comprises snooping,by the second wireless headphone, the audio information from the audiosource based on the communication parameters.
 19. The method of claim17, further comprising: establishing, by the second wireless headphone,the first type of short-range wireless communication with the audiosource; and transmitting, by the second wireless headphone,communication parameters indicative of the first type of short-rangewireless communication to the first wireless headphone, whereinreceiving, by the first wireless headphone, the audio informationcomprises snooping, by the first wireless headphone, the audioinformation from the audio source based on the communication parameters.20. The method of claim 17, wherein the error correcting message istransmitted to the second wireless headphone using a second type ofshort-range wireless communication different from the first type ofshort-range wireless communication.
 21. The method of claim 20, whereinthe first type of short-range wireless communication is BLUETOOTHcommunication, and the second type of short-range wireless communicationis WiFi communication or NFMI communication.
 22. A method for wirelesslycommunicating BLUETOOTH audio information, comprising: receiving aBLUETOOTH audio data packet from an audio source using BLUETOOTHcommunication; in response to successfully receiving the BLUETOOTH audiodata packet from the audio source, generating an error correcting codeby coding a payload of the BLUETOOTH audio data packet; andtransmitting, to a wireless headphone, an error correcting messageincluding the error correcting code without transmitting the BLUETOOTHaudio data packet.
 23. The method of claim 22, further comprising, inresponse to not successfully receiving the BLUETOOTH audio data packetfrom the audio source, transmitting a NACK message to the audio source.24. The method of claim 22, further comprising, in response to notsuccessfully receiving the BLUETOOTH audio data packet from the audiosource, transmitting a pseudo error correcting message without the errorcorrecting code to the wireless headphone.
 25. The method of claim 22,further comprising: establishing the BLUETOOTH communication with theaudio source; and transmitting, to the wireless headphone, communicationparameters indicative of the BLUETOOTH communication.
 26. The method ofclaim 22, further comprising receiving, from the wireless headphone,communication parameters indicative of the BLUETOOTH communication,wherein receiving the BLUETOOTH audio data packet comprises snooping theBLUETOOTH audio data packet from the audio source based on thecommunication parameters.
 27. A method for wirelessly communicatingBLUETOOTH audio information, comprising: receiving a BLUETOOTH audiodata packet only from an audio source using BLUETOOTH communication;receiving, from a wireless headphone, an error correcting messageincluding an error correcting code without receiving the BLUETOOTH audiodata packet; correcting the BLUETOOTH audio data packet from the audiosource based on the error correcting code; and in response tosuccessfully receiving the BLUETOOTH audio data packet after thecorrection, transmitting an ACK message to the audio source.
 28. Themethod of claim 27, further comprising, in response to at least one of(i) not successfully receiving the BLUETOOTH audio data packet after thecorrection, or (ii) not successfully receiving the error correctingmessage including the error correcting code from the wireless headphone,transmitting a NACK message to the audio source.
 29. The method of claim27, further comprising: establishing the BLUETOOTH communication withthe audio source; and transmitting, to the wireless headphone,communication parameters indicative of the BLUETOOTH communication. 30.The method of claim 27, further comprising receiving, from the wirelessheadphone, communication parameters indicative of the BLUETOOTHcommunication, wherein receiving the BLUETOOTH audio data packetcomprises snooping the BLUETOOTH audio data packet from the audio sourcebased on the communication parameters.
 31. A wireless audio system,comprising: a first wireless headphone configured to: receive, from anaudio source, audio information using a first type of short-rangewireless communication; in response to successfully receiving the audioinformation from the audio source, generate an error correcting codebased on the audio information; and transmit an error correcting messageincluding the error correcting code; and a second wireless headphoneconfigured to: receive, from the audio source, the audio informationusing the first type of short-range wireless communication; receive,from the first wireless headphone, the error correcting messageincluding the error correcting code; and in response to successfullyreceiving the audio information from the audio source based on the errorcorrecting code, transmit an acknowledgement (ACK) message to the audiosource, wherein one of the first and second wireless headphones works ina snoop mode to communicate with the audio source based on communicationparameters of another one of the first and second wireless headphones,the first type of short-range wireless communication is based on aplurality of slots with a same duration, the first wireless headphone isconfigured to receive at least part of the audio information andtransmit the error correcting message in a same slot, and the secondwireless headphone is configured to transmit the ACK message in animmediately subsequent slot.